Power driver for light emitting diode illumination and control method thereof

Abstract

A method of controlling a power driver for LED illumination may include receiving, by a power correction unit, an AC voltage from the outside, rectifying the received AC voltage into a DC voltage, and correcting a power factor of the rectified DC voltage; and receiving, by a DC/DC converter unit, the DC voltage from the power factor correction unit and converting the received DC voltage into a DC voltage which has a magnitude different from the received DC voltage and is supplied to an LED module. A skip control unit, which is disposed in the DC/DC converter unit, may be fed back with a current flowing in the LED module driven by receiving the output from the DC/DC converter unit to detect a magnitude of the current and output a signal for a skip mode control depending on the detected magnitude of the current.

What is claimed is: 
     
       1. A power driver for Light Emitting Diode (LED) illumination, comprising:
 a power correction unit receiving an AC voltage, rectifying the received AC voltage into a DC voltage, and correcting a power factor of the rectified DC voltage; and 
 a DC/DC converter unit receiving the DC voltage from the power correction unit and converting the received DC voltage into a DC voltage which has a magnitude different from the received DC voltage and is supplied to an LED module, 
 wherein the DC/DC converter unit comprises a skip control unit, to which a current flowing in the LED module driven by receiving an output from the DC/DC converter unit is fed back, to detect a magnitude of the current and to output a signal for a skip mode control depending on the detected magnitude of the current. 
 
     
     
       2. The power driver for LED illumination according to  claim 1 , wherein the DC/DC converter unit includes a DC/DC controller feeding back with the current flowing in the LED module to detect the magnitude of the current and controling a current flowing in a primary side winding of a transformer comprised in the DC/DC converter unit depending on the detected magnitude of the current. 
     
     
       3. The power driver for LED illumination according to  claim 2 , wherein the skip control unit comprises a processor comparing the fed back current with a reference current and outputting the signal for the skip mode control to the DC/DC controller depending on the comparison result. 
     
     
       4. The power driver for LED illumination according to  claim 2 , wherein the skip control unit includes:
 a comparator receiving and comparing a voltage signal sensed by an auxiliary winding disposed at the primary side wiring of the transformer and a skip carrier signal generated from a skip carrier generator, and outputting a skip mode operation signal when the sensed voltage is lower than a skip carrier level; and 
 an OR gate receiving and OR-operating an output signal from the comparator and a feedback signal from the LED module and outputting the signal for the skip mode control to the DC/DC controller. 
 
     
     
       5. The power driver for LED illumination according to  claim 2 , wherein the skip control unit receives a skip control signal from an external main control unit and transfers the received skip control signal to the DC/DC controller. 
     
     
       6. The power driver for LED illumination according to  claim 1 , wherein the power correction unit comprises a boost converter. 
     
     
       7. The power driver for LED illumination according to  claim 1 , wherein the DC/DC converter unit comprises an inductor-inductor-capacitor (LLC) resonance converter. 
     
     
       8. A method of controlling a power driver for LED illumination including a power correction unit and a DC/DC converter unit, the method comprising:
 receiving, by the power correction unit, an AC voltage, rectifying the received AC voltage into a DC voltage, and correcting a power factor of the rectified DC voltage; 
 receiving, by the DC/DC converter unit, the DC voltage from the power correction unit and converting the received DC voltage into a DC voltage which has a magnitude different from the received DC voltage and is supplied to an LED module; 
 feeding a current, which flows in the LED module driven by receiving an output from the DC/DC converter unit, back to a skip control unit comprised in the DC/DC converter unit; and 
 detecting a magnitude of the current and outputting a signal for a skip mode control depending on the detected magnitude of the current, by the skip control unit. 
 
     
     
       9. The method according to  claim 8 , wherein the outputting of the signal for the skip mode control by the skip control unit includes:
 receiving and comparing, by a comparator, a voltage signal sensed by an auxiliary winding disposed at a primary side of a transformer and a skip carrier signal generated from a skip carrier generator, and outputting a skip mode operation signal when the sensed voltage is lower than a skip carrier level; and 
 receiving and OR-operating, by an OR gate, an output signal from the comparator and a feedback signal from the LED module and outputting the signal for the skip mode control to the DC/DC controller. 
 
     
     
       10. The method according to  claim 8 , wherein the outputting of the signal for the skip mode control by the skip control unit comprises:
 directly receiving a skip control signal from an external main control unit by the skip control unit; and 
 transferring the received skip control signal to the DC/DC controller.